Stripe matching machine



Mllth 1'3, 1956 D V. THQMPSQN STRIPE MATCHING MACHINE 25 Sheets-Sh -t l iva/.

Filed Feb. 19, 1952 March 13, 1956 D THQMPSQN 2,737,700

STRIPE MATCHING MACHINE Filed Feb. 19. 1952 3 Sheets-Sheet 2 3 Sheets-Sheet 3 Filed Feb. 19. 1952 .Had

STRIPE MATCHBN G MACHINE Daniel Varney Thompson, Ipswich, Mass., assignor, by

mesne assignments, to Tubular Textile Machine Corporation, Woodside, N. Y., a corporation of New York Application February 19, 1952, Serial No. 272,483

6 Claims. (Cl. 26-51.v5)

This invention relates to improvements in stripe matching machines. More particularly, the invention is concemed with an automatic registering mechanism for such machinery.

Transversely striped knitted goods produced on circular knitting machines is produced in tubular form and requires splitting longitudinally and stitching the split edges back together in order to produce goods in which the courses and wales are properly disposed at right angles to each other and each stripe is a continuous band running around the tubular fabric.

Narrow striped material may have the stripes running helically so that in a piece of goods having a repeated pattern including, for example, blue, green, red and yellow stripes, a stripe of each color will be a continuous helix running the full length of the goods. Such material requires splitting, displacing one split edge with reference to the other by the width of the complete pattern of stripes which is duplicated along the fabric and then sewing the `goods together again with the stripes matching, so that the piece is converted from one having helical stripes running its full length to one having a succession of stripes, each of which is a band running completely around the fabric tube.

In wider striped material, the stripes may not be helical but the change from one color yarn tov another creates a longitudinal strip in the goods where the yarn color is rchanged.` Each stripe as it enters this strip being displaced longitudinally of the tube with reference to the same stripe as it continues on the other side of the strip and there being also certain other irregularities inthe stitch formation in this strip,1such goods requires to be split along the strip where the color changes are effected and to have the stripes brought back together` and stitched in registry to produce the desired regular fabric.

Machinery for effecting the required stripe matching is well known and has generally been operated manually so far as making the required adjustment for bringing the stripes into registry before stitching the split fabric tube back together again.

As will be apparent in the following description, photocell registry control systems of usual and known type are not adaptable to stripe matching of knitted goods.

It is an object of the invention to provide a photoelectrically controlled registration mechanismfor stripe matching of such knitted goods.

A further object of the invention is to provide a registering system capable of operating on a variety of fabrics having stripes of various colors `and of various widths arranged in a variety of different orders, without necessitating complicated or delicate adjustments in the registering mechanism.

A still further object of the invention is to provide a registering system of stripe matching capable of operating on simple belt drives and not requiring complicated differential or other gearing.

With the foregoing objects as well as others which will appear yin the following description in mind, a ma- United States Patent O ICC v e I2 chine embodying the invention in a preferred form will now be fully described with reference to the accompanying drawing and the features forming the invention will then be specifically pointed out in the appended claims.

In the drawing:

Figure 1 is a floated schematic isometric view of a stripe matching machine embodying the invention in a preferred form;

Figures 2 and 3 are, respectively, isometric views of a section of tubular knitted fabric before and after matching of the stripes;

Figure 4 is a plan view of the mechanism of Figure 1; and

Figure 5 is a schematic circuit diagram of the control system employed with the photoelectric scanning devices used for matching the stripes.

Referring now to Figures 1 and 2, a generally conventional stripe matching machine is shown, the tubular knitted fabric F to be matched is supplied from a roll 1, being fed by driven roller 2 and cooperating idle roller 3, being conditioned by a steam cylinder 4 and then passing over the usual spreader at 5, which element is supported by a stud shaft 6 and also rests upon a driven roller 7, and cooperates with a slitter wheel 8, as indicated. The slit fabric now passes between rollers 9 and 10, after which the slit edges are separated as shown, the fabric being spread apart to form upper and lower courses `adjacent the slit edges. The upper course passes over an idle divider roller 11, between this roller 11 and a driven drive roller 12 cooperating therewith, while the lower course passes over a second divider roller 13.

The two courses come together again on idle roller 14, passing between driven roller 15 and idle roller 16, after which they are again separated, passing over the air tubes 17 and 18 to straighten the two edges of the cloth preliminary to stitching, in the usual way. The two edges are again brought together at the sewing head, indicated schematically at 20, which serves in the usual manner for stitching the edges together and trimming the edges beyond the stitch line. The trimmed off edges pass between driven and idle drag rollers 21 and 22 into `a box or other suitable container 23,V while the stitched lspreader 33 floated within the fabric tube for permitting examination of the matching of the stripes.

As indicated in Figure 4, the slitter disc 8 may have its own separate drive motor, the remainder of the driven rollers may be driven by a suitable pulley drive and cross shafting fromV a common motor 34, and a separate drive motor 35 is provided for the roller 12.

A striped fabric in which the pattern may run spirally, as indicated in Figure 2, is fed into the machine manually in the usual way and the slit edges are displaced with relation to each other so as bring them into or close to a matching relationship, such as indicated in Figure 3.

To permit variation in the length of the two courses ot' the fabric approaching roller 14 for producing such registry, the divider roller 13 is mounted on a stub shaft'36, which is carried eccentrically by a shaft 37, the angular position of which may be regulated by a worm wheel and worm and crank arrangement 38 (Figure 4) for adjusting the position of roller 13 as indicated by the broken arc 40 in Figure 1. After the threading and preliminary manual registration `of the fabric, the machine drive is v.turnedonand thereafter the. registration isaccomplished automatically by the mechanism now to be described.

The scanning heads 31 and 32 may be of conventional "Htyp'e. available commercially forl such .purpose as cut sofi -"register control," and mayf' be" designed: to respond 'either 'to ardecreasev in lightfintensity or.an=increase in :light intensity,=as desired, it being indifferent which operation is selected, but it will be assumed fondeniteness. that the yscanning'heads kand associatedcircuits respond to a decrease in illumination.

As indicated schematically in Figure 5, lmotor 34 1s thyratron controlled in a known and usual way, having a -=-ii`eld` F34 energized vfrom a suitableV power vsource,:.not

shown, and armature 3d supplied with current-from a n thyratroncontrol of usual type"indica'ted schematically at THY-l. The current supplied is regulated by the motor speed control, balancing an adjustable voltage against the HVvoltage .induced in iield f34 of the motor,V so that the speed of motor 34 corresponds to ythe set voltage in the `motor `speed control. The-speed ratio lcorresponding to a' given motor speed control setting may be adjusted. by

means of potentiometer Sti, in which-the control voltage 1 Vfor the thyratron control unit is'developed. The control Avoltage applied to the thyratron control unit THY-1 is alsov applied across potentiometer 51, so that a desired Aand adjustable fraction of this voltage may be applied to thyratron control unit THY-2, supplying current to armature A35 of the motor 35. This motor may be identical in construction to the motor A34 and has a field F35 energized similarly to the field F34. Field 135 of :the motor A35 is, however, utilized for` further varying the speed o the motor 35 about the value preset by ad- .f .justing potentiometer i.

1 'The current in field f35 is regulated according to the 1 scanning head readings, as indicated.

'Thesignals'S31 and S32, developed in the scanning f heads`31 and 32, pass to an electronic time discrimiuator,

: which may be of any desired type, such as a four triode lbridge circuit for comparing the signals and producing an output error signal proportional to the lead of the signal pulses received from one of the-scanning heads was compared to the other.

For definiteness, itmay be assumed that a positive error signal is produced when the stripes reaching scanning head 31 lead the correspond- `ring stripes reaching the scanning head 32,A and a negative 5 :signal when the reverse occurs. -The error signal isnow fed to an error signal integratorand amplifier, which supplies current to the field f of motor 3'5` for varying -the speed of this motor.

'Variation in the speed of motor135- varies the speedfof rotation of the driven roller 12 cooperatingwith divider 11, thus varying the tension on the upper course of the ffabric. If thek stripes reaching 'scanning head 31 lead the .v stripes reaching scanning head 32, the currentin'reldf35 will -change so-as to decrease thespeed-of motor 35 and roller 12, thus slowing down` the Aupper course'v ofthe fabric-until? registration is restored. Conversely, if the stripes reaching the scanning head *31 lag-'behind Ythe 1 stripes reaching the scanning-head 32, Ythe current in field f35 will be altered to speed up the roller 12, thus reducing the tension on the upper lc'ourse of the kfabric and `permitting it to .advance until registration s.- again restored.

' The error signal integratorand amplier, indicatedin Figure 5,-may-V have a suitable-resistance network'for integrating the error signal and which may be a-djusted'to any desired value, the time constant being selected so as to produce the required accuracy of registration without hunting.

' Since a system of the character indic'atedmayoperate to 'eliminate error exponentially,` oversliooting'and hunting is-readiIy avoidedwithout sacrificing `speed of response,

providing thata small dead zone exists.

Y.,Since stripe registration within a sixteenth. of aninch ton-so isiclose enoughforall-j practical purposes, .the

registering system may operate with a small dead zone,

. .and any tendency to hunt or overshoot nlmakngrequired corrections is easily avoided.

It will be observed that the register control system of the present invention differs markedly from usual systems, in that the time of arrival of a stripe at a scanning head is not controlled with reference to the position of any machine element, as, for example, with reference to the angular position ofV one ofthe rollers. The registering system is, therefore, venabled to work with a stripe matching machine having belt drive as shown, even though there may be a certain amount of, slip and consequent variation in angular positionof the various rollers. It is `also to be notedthat the timeof arrival'of.the stripes at the scanning heads may be quite variable, in view of the relatively great elasticity or stre'tch'of the knitted goods. Since, however, one course of fabric is being compared with another, no difficulty is experienced due to variation in thestretch of the fabric.

ltshouldalso be noted that-,the stripematchingmachine may be called uponv to match fabric in--whichethe width of stripe, number of different colors andthe'lcolors themselves may be varied :almostwithout; limit. "The photocell scanning mechanisms will; aswusual, exhibit a vdifference in response to different colors.t The;,time-discriminator may, however, readily bedesignedv so. as.- to

ignore diterence in amplitude ofthe signals from-the yscanning'heads and lthe averaging of Vthe :signals prior to amplification and feeding to the field ,f35f permits a `wide f range of variation in stripe width, number of colors and the colors involved without affecting the operation-,ad-

" Versely.

.What is claimed is: l. ln a stripe matching machine hayingmeansxgfor; slit- 'ting a tubular fabric along one 'side and -rejoiningA-the slit edges together for matching stripes, and'including rolls for advancing the slitfabric to the rejoining` means, and in combination, a separator plate for'separating,arr-upper and lower course of the slittubularffabric as it passes to they rejoining means, a pair of photoelectric scanning heads-responsive to the passage offthestripes-onfthe two sides of the separating plate, a control circuit-'responsive -to the scanning heads for producing an-error signal corresponding to the lead of the-stripes onone side ofthe separating plate as compared with those on theother;y and -,.means controlled-by the control circuit-for var-yinggthe tension on one of the saidcourses to registerthe stripes.

2.4 In a stripe matching machine-having means for slitting a tubular -fabric along;one Yside and-frejoiningmthe f slit edges together for matching stripesgaand. including rolls for advancing the slit fabric-tothe rejoining means,

= and-in combination, aseparatorplate forseparatingan upper and :lower course of 'the slit tubular -fabric-as it passes; to the rejoiningmeans, a1 pair of iphotoelectric scanning-heads responsive to the passagefof-fthestripes on-thet-worespective sides of rtheseparating-plate, a con- ,-:trolfcircuit responsive to the scanning,y heads fand including a time discriminator for producing an-error-fsignal corresponding to the-lead of the `stripes on one vside of the separating plate as `compared with thoseon theother; and means controlled by the control'circuit yfor varying the tension onone of said courses to registerthe.V stripes.

3l A stripe matching-.machine according. tofclaim 2;, in `which the control circuit lalso comprises-means. forintegrating the vdiscriminator output Vfor producingan error 'signal corresponding to the averagelead over a-predeter- `imined time interval.

4. In a stripe matching vmachine having means for slit- 4.,-ting a tubular fabric along one side andreioining the slit :rnachinedrive generally, aseparatorplate for separating .theupperand lowercourse'of the slit ytubulaizfabric` as it passes to the rejoining means, a pair of photoelcctric scanning heads responsive to the passage of the stripes on the two sides of the separating plate, a control circuit responsive to the scanning heads for producing an error signal corresponding to the lead of the stripes on one side of the separating plate as compared with those on the other, and means controlled by the control circuit for varying the speed of the said tension control motor to Vary the tension on the course engaged thereby to register the stripes.

5. A stripe matching machine according to claim 4, comprising also adjustable means for driving the said tension control motor at a predetermined selected speed ratio to the machine drive generally, and in which the said means controlled by the said control circuit comprises means for-varyng saidvratio in response to said error signal.

6 v 6. A stripe matching machine according to claim 5, in which the means for varying the said ratio comprises a tension control motor eld Winding and means controlled by the control circuit for varying the current through said field winding.

References Cited inthe le of this patent UNITED STATES PATENTS 2,106,612 La Pierre et al Jan. 25, 1938 2,196,893 Berry Apr. 9, 1940 2,209,220 Berry July 23, 1940 2,233,644 Smiley Mar. 4, 1941 2,467,281 Walter et al. Apr. 12, 1949 

